JPH08673Y2 - Reflective real projector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a reflection type real projector, and more specifically, a projection source such as a manuscript is illuminated by a light source through a reflection mirror, and its irregular reflection light is emitted. The present invention relates to a method of irradiating an object to be projected in a reflection type real projector in which an image is formed on a projection surface via a projection mirror and a projection lens.

(Prior Art) Conventionally, as a real-life projector, as shown in FIG. 7, a projection object placed on a stage 11 made of glass or the like is used as a light source.
The method of directly irradiating with 12 is common. In the figure, 13 is a projection mirror for reflecting the reflected light from the object to be projected, 14 is a projection lens, and 15 is a casing.

Regarding the irradiation method of the projection object in this projector, as a first condition, the irradiation light from the light source 12 is regularly reflected by the projection object or the stage 11 based on the law of reflection, and the regularly reflected light is the projection mirror. It is necessary to prevent the deterioration of the resolution of the projected image due to the regular reflection light by disposing the light source 12 at a position where it does not enter the projection lens 14 via 13. Further, as the second condition, it is necessary to set the position of the light source 12 so that the light source 12 does not enter within the viewing angle of the projection lens 14. Further, as the third condition, in order to illuminate the stage 11 uniformly, it is necessary to install the light source at a considerable distance from the stage 11, but in reality, due to the size of the projector, etc. Since the optical path cannot be taken so long, the light source 12 with a small luminous flux is used to illuminate the stage 11 from the side.

Taking the above conditions into consideration, in the projector shown in FIG. 7, in consideration of the size of the stage 11, the viewing angle of the projection lens 14, etc., the projector 11 should be positioned below both sides of the stage 11 in an appropriate manner. An illuminating method is adopted in which a plurality of light sources 12 are installed so as to be spaced apart and have an appropriate irradiation angle.

However, in order to provide more uniform illumination, the light source 12
If the projector is placed as far away as possible from the stage 11, the projector inevitably becomes large in the width and height directions, and due to the large number of light sources, the weight increases, the cost increases, the structure becomes complicated, and the projector is transported. And installation is inconvenient.
On the contrary, in order to downsize the projector, the light source 12 is changed to the stage 11
If it is too close to, there is an inconvenience such as uneven illuminance on the object to be projected.

In view of these problems, the light source 12 is provided in front of the projector so as to face the projection mirror 13 as shown in FIG. 8 mainly for the purpose of downsizing the projector and eliminating unevenness in illuminance. There is proposed a reflection type real projector according to Japanese Utility Model Laid-Open No. 61-11148 in which light from a light source 12 is reflected by a projection mirror 13 to irradiate a projected object on a stage 11.

On the other hand, as shown in FIG. 9, for the purpose of uniformly illuminating the projected object and improving the illumination efficiency,
A plurality of irradiation mirrors 16 each having a shape that expands upward and forward are provided around the projection mirror 13, and irradiation from the light source 12 is performed using these irradiation mirrors 16 and projection mirror 13. A reflection type real projector according to Japanese Utility Model Laid-Open No. 61-16544, which reflects light toward the stage 11, has been proposed.

(Problems to be solved by the invention) However, in the actual projector shown in FIG.
A light source 12 is arranged at a position opposite to 13, and the light from the light source 12 is reflected by the projection mirror 13 and illuminates the stage 11 and the object to be projected from a substantially vertical direction.
In this case, the regular reflection light (specular reflection light) from the projection object or the like due to the irradiation light is reflected in a substantially vertical direction according to the law of reflection, and this regular reflection light enters the projection lens 14 via the projection mirror 13. This is the cause of so-called halation, which significantly deteriorates the resolution of the projected image.

Further, the actual projector shown in FIG. 9 includes a projection mirror 13 and a plurality of irradiation mirrors 16 provided separately from the projection mirror 13.
Since all the light from the light source 12 is directed toward the stage 11 to increase the illumination efficiency, it is necessary to prevent the regularly reflected light according to the law of reflection from entering the projection mirror 13. However, there is a drawback that the structure of the projector becomes complicated because the use mirror 16 becomes multi-faceted as a whole. At the same time, in order to use the projection mirror 13 also as an irradiation mirror, the light sources 12 are arranged on both sides of the projection mirror 13 so that the light sources are arranged.
The positional relationship must be such that a part of the irradiation light from 12 is incident on the projection mirror 13, and in combination with the complicated structure of the irradiation mirror 16 as described above, the actual projector is projected laterally (projection). It has a drawback that it becomes large in the width direction of the use mirror 13.

The present invention has been proposed in order to solve the above-mentioned problems, and its object is to project inside the reflection mirrors on both sides of the stage and in front of the projection mirror, and to project through the reflection mirrors. Halation of the projected image is eliminated by arranging the light source so that the regular reflection light from the object and stage does not enter the projection lens and the real image and virtual image are located outside the viewing angle of the projection lens. An object of the present invention is to provide a reflection type real projector in which the length of the optical path to the stage is increased to perform uniform illumination, and the projector is downsized and lightened and the structure is simplified.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides reflection mirrors for reflecting light from a light source and irradiating a projection object on a stage on both front sides of the projection mirror. The light sources are provided so as to face each other, and the light source is forward of the projection mirror and inside the reflection mirror, and the regular reflection light from the projection target and the stage due to the reflection light through the reflection mirror is projected onto the projection lens. It is characterized in that it is arranged such that it does not enter and the real image and virtual image of the light source exist outside the viewing angle of the projection lens.

Further, in the present invention, it is preferable that the reflection mirrors are provided parallel to each other and perpendicular to the stage. Further, when the light source is arranged in front of the width of the projection mirror, it is necessary to provide a light blocking member for directly blocking light on the projection mirror side around the light source. In addition, in order to cool the inside of the projector, it is desirable that the air sucked from the outside by the cooling fan is passed along the inner surface of the stage and then exhausted through the vicinity of the light source.

(Operation) According to the present invention, by providing the reflection mirrors on both front sides of the projection mirror and arranging the light source at the above position, the projection object and the stage by the irradiation light through the reflection mirror are The regular reflection light of (1) does not enter the projection lens through the projection mirror or directly, and at the same time, the direct light from the real image and the virtual image of the light source does not enter the projection lens. That is, since only diffused light (scattered light) from the object and the stage reflected by the projection mirror is incident on the projection lens, halation does not occur in the projected image.

Also, from the positional relationship of irradiating the stage using the reflected light from the light source by the reflection mirror, apparently, of the light source,
The stage illuminates by the virtual image existing outside the reflecting mirror, so that the optical path length can be sufficiently long despite the fact that the actual light source exists inside the projector. Therefore, even if an actual light source is not provided below both sides of the stage, even if the number of light sources is relatively small, uniform illumination can be performed.

Furthermore, by providing the light source in front of the projection mirror and inside the reflection mirror, it is possible to reduce the size of the projector in the width direction. In particular, if the reflection mirrors are provided parallel to each other and perpendicular to the stage. The structure is simplified, and all the components of the actual projector are housed in a narrow rectangular parallelepiped space, which simplifies the structure of the projector and further downsizes it.

In addition, the light blocking member attached to the light source, when the light source is arranged in front of the width of the projection mirror, the light from the light source directly or through the projection mirror irradiates the projection target and the stage. It acts to prevent the regularly reflected light from entering the projection lens via the projection mirror.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

First, FIGS. 1 to 4 show a first embodiment of the present invention. In FIGS. 1 and 2, reference numeral 1 denotes a rectangular parallelepiped casing, and the inner surfaces of both side plates of the casing 1 face the front sides of the side plates so that the reflection mirrors 2A and 2B are parallel to each other. And installed respectively. Here, the reflection mirrors 2A and 2B may be formed to have substantially the same length as the side plate. In addition, on the upper surface of the casing 1,
A stage 3 through which the reflected light from the reflection mirrors 2A and 2B is transmitted is provided, and the reflection mirrors 2A and 2B and the stage 3 are in a positional relationship orthogonal to each other. The stage 3 is made of glass and has a predetermined size such that a document to be projected or a projection object (not shown) such as a three-dimensional object having a slight thickness can be placed.

Further, inside the casing 1, there is provided a projection mirror 4 for receiving the reflected light from the projection target on the stage 3, and the projection mirror 4 is shown in FIGS. 1 and 2 (c).
As is clear from the figure, they are arranged at an angle of about 45 ° with respect to the horizontal plane. The projection mirror 4 has a substantially trapezoidal shape, and its long bottom side is close to one end side of the stage 3.
A projection lens 5 that collects the reflected light from the projection mirror 4 is provided on the front surface of the casing 1.

Further, in the casing 1, light sources 6A and 6B including halogen lamps and the like are arranged in front of the projection mirror 4 and inside the reflection mirrors 2A and 2B, respectively. These light sources 6A and 6B are arranged such that the centers of their optical axes face the insides of the reflection mirrors 2A and 2B, and more specifically, the light reflected by the reflection mirrors 2A and 2B is in the entire area of the stage 3. As shown in FIGS. 1 and 2 (a) and 2 (b), it is necessary to irradiate the front side with respect to the center of the reflection mirrors 2A, 2B, and the reflection mirrors 2A, 2B from below. It is placed in a position that illuminates.

More importantly, the light sources 6A and 6B are the reflection mirror 2
The regular reflection light based on the law of reflection from the object to be projected and the stage 3 by the irradiation light through A and 2B does not enter the projection lens 5 through the projection mirror 4 but also directly enters the projection lens 5. Is placed at a position where
In addition, the light source 6 shown in FIGS. 1 and 2 (a), (b)
The A, 6B (real images) and the virtual images 6a, 6b are arranged at positions such that they exist outside the viewing angle of the projection lens 5. That is, the light source is located at such a position that only the light reflected by the projection mirror 4 from the irregularly reflected light (scattered light) from the object to be projected and the stage 3 due to the irradiation light through the reflection mirrors 2A and 2B is incident on the projection lens 5. 6A and 6B are arranged.

As long as the above conditions are satisfied, the light sources 6A and 6B can be arranged not only at the positions shown in FIGS. 1 and 2 but also further inward and inside the width of the projection mirror 4, respectively. As such a position, for example, the position shown in FIG. 3 can be considered. In this case, the direct light from the light sources 6A and 6B is reflected by the projection mirror 4 to irradiate the stage 3 and the projection object from the vertical direction. There is a possibility that the regular reflected light is reflected in a substantially vertical direction and enters the projection lens 5 via the projection mirror 4. Therefore, in order to prevent this, as shown in FIG. 3, appropriate light-shielding members 7A and 7B that cover the periphery of the projection mirror 4 side of the light sources 6A and 6B are attached, and the light sources 6A and 6B and the light-shielding member 7 are attached.
Critical line L _{1 of} direct light determined by the positional relationship with A and 7B,
It is necessary to consider that the projection mirror 4 is located in L ₂ .

Next, this operation will be described. Light from the light sources 6A and 6B is reflected by the reflecting mirrors 2A and 2B on both sides as shown in FIGS. 1 and 2A and 2B, respectively, and the stage Irradiate the entire surface of 3 obliquely from below. At this time, the stage 3 is apparently viewed from below by the virtual images 6a and 6b located outside of the stage 3 via the reflecting mirrors 2A and 2B.
The stage 3 is illuminated and the optical path length between the stage 3 and the virtual images 6a and 6b is ensured to be sufficiently long.
A substantially uniform illumination is provided over the entire surface. Therefore, the intensity of the reflected light from the projection target placed on the stage 3 becomes substantially uniform, and this reflected light is reflected by the projection mirror 4 and condensed by the projection lens 5, and the projection lens 5 The projection image of the projection target is formed on the projection surface outside the distance determined by the focus.

At this time, the light sources 6A and 6B as described above, the reflection mirror 2A,
Depending on the positional relationship between 2B and the projection mirror 4, the projection lens 5
The normal reflection light from the object to be projected and the stage 3 does not enter indirectly or directly through the projection mirror 4, and the direct light from the real and virtual images of the light sources 6A and 6B. Since it does not enter, it is possible to completely prevent the halation phenomenon that the resolution of the projected image is deteriorated by the regular reflection light or the direct light.

At the same time, by arranging the light sources 6A and 6B inside the reflection mirrors 2A and 2B in front of the projection mirror 4 as described above, and by adopting the light shielding members 7A and 7B as described above, if necessary, Since it is possible to prevent incident of reflected light or direct light and to secure the optical path length, the width direction of the actual projector (reflection mirror
The distance in the direction orthogonal to the surfaces 2A and 2B) can be shortened, and theoretically, the actual projector can be downsized to the full width of the stage 3. Moreover, since each component of the actual projector can be housed in the rectangular parallelepiped space, the structure can be simplified and further downsized.

However, in this type of real projector, the light sources 6A and 6B generate a considerable amount of heat and the inside of the casing 1 becomes high in temperature, which damages the components of the projector and the projection target placed on the stage 3. Therefore, the inside of the casing 1 is forcibly cooled because it may be damaged.
Hereinafter, the cooling method in the above embodiment will be described.

FIG. 4 is an internal configuration diagram of the actual projector corresponding to FIG. 2C, in which 8 is a cooling fan provided below the projection mirror 4 and 9 is above the projection lens 5. The reference numeral 19 designates a vent hole provided under the light sources 6A and 6B, respectively. With the above configuration, the air sucked into the casing 1 from the cooling fan 8 reaches the upper portion of the casing 1 from the rear surface of the projection mirror 4 and moves forward along the inner surface of the stage 3 as shown in FIG. To do. As a result, the stage 3 is directly and efficiently cooled, and there is no fear of damaging a projection object such as a document placed on the stage 3 due to high heat.

Further, part of the air after cooling the stage 3 is exhausted from the ventilation port 9, but the remaining air is exhausted from the ventilation port 10 below via the vicinity of the light sources 6A and 6B. This allows the light source
Since 6A and 6B are also well cooled, there is no risk of the inside of the casing 1 becoming hot.

If the surroundings of the light sources 6A, 6B are surrounded by an appropriate casing (not shown) within a range that does not block the light emitted from the light sources 6A, 6B, the heat radiation from the light sources 6A, 6B is reduced, Further cooling effect can be achieved. The casing in this case may be configured to also serve as the light shielding members 7A and 7B. Furthermore, if heat ray transmitting mirrors are used for the reflecting mirrors 2A and 2B, it is possible to further prevent the temperature rise of the stage 3.

Next, FIGS. 5 and 6 show second and third embodiments of the present invention, respectively. In these examples, the projection lens 5
By arranging a plurality of light sources on both sides of the above, it is intended to realize brighter and more uniform illumination than in the first embodiment.

That is, in the embodiment of FIG. 5, the light sources 6A ₁ , 6A ₂ and 6B ₁ , 6B ₂ are arranged on both sides along the axial direction of the projection lens 5, respectively. In this case, the light sources 6A ₁ and 6A ₂ and 6B
_In order to illuminate the stage 3 uniformly regardless of the positional deviation between ₁ and 6B ₂ , adjacent light sources have their center lines parallel to the optical axis so that the incident angles of the irradiation light on the reflecting mirrors 2A and 2B are slightly different. Is not. Further, in the embodiment of FIG. 6, the projection lens 5
The light sources 6A ₁ , 6A ₂ and 6B ₁ , 6B ₂ are arranged on both sides along a direction (height direction of the projector) orthogonal to the axial direction of. Also in this embodiment, the center lines of the optical axes of the light sources 6A ₁ and 6A ₂ and 6B ₁ and 6B ₂ are not parallel in order to uniformly illuminate the stage 3.

The light sources 6A ₁ , 6A ₂ , 6 in these second and third embodiments
Similarly to the first embodiment, B ₁ and 6B ₂ can reflect the reflected light from the reflecting mirrors 2A and 2B through the stage 3 and can be reflected from the projected object and the stage 3. The normal reflection light of 6 does not enter the projection lens 5 indirectly or directly, and the light sources 6A ₁ , 6A ₂ , 6B ₁ and 6B ₂ are arranged at positions such that the real and virtual images are outside the viewing angle of the projection lens 5. is necessary. If necessary, the light shielding member shown in FIG.
7A and 7B are attached to the light sources 6A ₁ , 6A ₂ , 6B ₁ and 6B ₂ , and the 4th
It is desirable to adopt the cooling method as shown in the figure.

It should be noted that the number of light sources is not limited to the above-mentioned embodiments, and a larger number can be used.

(Effect of the Invention) As described in detail above, according to the present invention, the reflection mirrors are provided on both sides of the projection mirror, and the light source is provided in front of the projection mirror and inside the reflection mirrors facing each other. The regular reflected light from the projection target and the stage due to the reflected light through the reflecting mirror does not enter the projection lens,
Moreover, by arranging the real image and the virtual image of the light source at positions outside the viewing angle of the projection lens, the following effects can be obtained.

That is, first, the regular reflection light and the direct light from the light source do not enter the projection lens, and only the light that is the irregular reflection light (scattered light) from the projection target and the stage reflected by the projection mirror enters the projection lens. Therefore, it is possible to obtain a high-resolution projected image without causing halation in the projected image.

Second, since the light source is provided inside the reflecting mirror and its virtual image exists outside the projector, and the virtual image illuminates the stage, the actual light source exists inside the projector. In spite of this, it is possible to secure a sufficiently long optical path length and perform uniform illumination. In other words, it is not necessary to install the actual light source considerably away from the stage or to provide a large number of light sources in order to achieve uniform illumination. It is possible to reduce the weight, reduce the price, and simplify the structure. With this, it is possible to obtain a real projector that is convenient for transportation and installation.

Thirdly, since the light source is provided inside the reflection mirror, the projector can be further downsized, and the stage can be downsized to the maximum width.

Fourth, since the shape and structure of the reflecting mirror may be simpler than that of the conventional multi-faceted irradiation mirror, the internal structure is not complicated, and all the components of the actual projector are It can be accommodated in a narrow rectangular parallelepiped space, and simplification of the structure of the projector can be achieved.

[Brief description of drawings]

1 to 4 show a first embodiment of the present invention. FIG. 1 is a perspective view showing the internal structure, FIG. 2 (a) is the same plan view, and FIG. 2 (b) is the same front view. FIG. 3C is a side view of the same, FIG. 3 is a plan view showing a modification of this embodiment,
FIG. 4 is a side view showing an internal cooling method, FIG. 5 shows a second embodiment of the present invention, FIG. 4 (a) is a plan view showing the internal structure, and FIG. FIG. 6 shows a third embodiment of the present invention. FIG. 6 (a) is a plan view showing the internal structure, FIG. 6 (b) is the same front view, and FIGS. It is a perspective view showing the internal structure of. 1 ... Casing, 2A, 2B ... Reflection mirror 3 ... Stage, 4 ... Projection mirror 5 ... Projection lens 6A, 6A ₁ , 6A ₂ , 6, 6B ₁ , 6B ₂ ... Light source 6a, 6b ... Virtual image, 7A, 7B … Shading member 8… Cooling fan, 9, 10… Vent

Claims (3)

[Scope of utility model registration request] 1. A light source and light emitted from this light source are transmitted,
Further, a stage on which the object to be projected can be placed, a projection mirror that reflects the reflected light from the object to be projected, and the reflected light from the mirror for projection is condensed to form a projected image of the object to be projected to the outside. In a real projector equipped with a projection lens for forming an image on the projection surface of, reflection mirrors for reflecting light from the light source and irradiating the projection target through the stage are provided on both sides of the projection mirror. The light sources are provided in opposition to each other, and the light source is in front of the projection mirror and inside the reflection mirror, and the regular reflection light from the projection target and the stage due to the reflection light through the reflection mirror is A reflection type real projector characterized in that it is arranged so that it does not enter the projection lens and the real image and virtual image of the light source exist outside the viewing angle of the projection lens. 2. The reflection type real projector according to claim 1, wherein the reflection mirrors are provided in parallel with each other and perpendicular to the stage. 3. A reflection-type real projector according to claim 1, further comprising a light-blocking member for blocking direct light from the light source to the projection mirror on the projection mirror side around the light source. .